Abstract/Description

With the intensification of pig production in some countries and the consequent problem of disposing manure, there is considerable interest in the traditional Chinese method of raising fish in ponds by feeding them with pig manure. Researchers at...

Notes

With the intensification of pig production in some countries and the consequent problem of disposing manure, there is considerable interest in the traditional Chinese method of raising fish in ponds by feeding them with pig manure. Researchers at the Asian Institute of Technology have been investigating the system and have found it is best suited to warmer areas of the world, where water temperatures exceed 20°C. The fish species most appropriate to the system are Chinese and Indian carp, common carp, tilapia, mullet and silver-striped catfish.
Pig manure itself has little value for the fish, but its fertilizing effect encourages the growth of phytoplankton, which is filtered out of the water by the fish. The production of phytoplankton does, however, brings problems. Photosynthesis can lead to high oxygen levels during the day but at night the oxygen is taken up by the phytoplankton. When oxygen levels fall to zero by the morning, this can be critical for some species of fish.
In Thailand, a yield of 5 tonnes of tilapia has been harvested annually from one hectare in ponds manured by 150 pigs.
Yields can be further boosted with the use of supplementary feed, such as soya bean cake, rice bran and pelleted feed
For further information consult:
Pig International Sept 1985 Watt Publishing Co 18 Chapel Street Petersfield Hants GU32 3DZ IIK